THE MICA DEPOSITS OF ALABAMA 



PART I. 



GENERAL DISCUSSION. 

 INTRODUCTION. 



FROM its indispensable character in many vitally im- 

 portant industries, and by reason of the failure as 

 yet to find or provide a satisfactory substitute for it in 

 certain of its most important and rapidly increasing 

 uses, mica has become one of the most essential and there- 

 fore valuable of all the mineral products. 



Although one of the most widely distributed of all 

 minerals as a component part of the various rocks, work- 

 able deposits of mica, from which may be recovered the 

 grades and the quality chiefly in demand, are not only 

 limited in number, but are also at very many points of 

 origin, inaccessibly located with respect to transportation, 

 and largely handicapped as to economic recovery by the 

 irregularities and uncertainties always incident to its 

 mode of occurrence. 



Of the distinct varieties of mica occurring in the Unit- 

 ed States, six have been to greater or less extent mined, 

 viz: muscovite, phlogopite, roscoelite, lepidolite, biotite, 

 and mariposite. Only two of these varieties, muscovite, 

 and phlogopite, have received any general application in 

 the industries, and have constituted therefore the major 

 part of present mine recoveries. 



As regards extent and availability, and their more com- 

 prehensive uses, indispensable to the electrical industry 

 as a vital factor in its enormous expansion, the varieties 

 of muscovite, having the same chemical composition and 

 varying only in physical characteristics, are the basic 

 factors at the present time in domestic mica mining and 

 manufacturing. 



Phlogopite, next in order of commercial importance, 

 is of small and infrequent domestic occurrence, the sup- 



